Marking station for timber

ABSTRACT

A marking station for defect locations and quality limits in timber includes a timber transporting device, a transporting speed changing device, and an indicating station part with a laser transmitting element formed as a mirror, and laser. The laser is arranged stationary so that the laser beam extends parallel to a movement direction of the timber and impinges on the mirror. The mirror deviates the laser beam transversely to the movement direction. The laser beam indicates on the timber, in the movement direction, a first separating plane before a defect location and a second separating plane behind the defect location. The laser beam also indicates quality limits. Indicating positions of the laser transmitting element are transmitted to a computer.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of U.S. patent applicationSer. No. 322,076 filed on Mar. 10, 1989, and entitled "Marking Stationfor Timber", now U.S. Pat. No. 4,934,229.

BACKGROUND OF THE INVENTION

The present invention relates to a marking station for timber. Moreparticularly, it relates to such a marking station which is used fordefect locations and quality limits in timber and provided with atransporting device, a device for changing a transporting speed of thetimber, and an indicating station part with a laser transmitter elementfor indicating first and second separating planes before and after adefect location and quality limits with a laser beam. The lasertransmitter element can be moved by an operator along a guiding deviceparallel to the movement direction to indicating positions correspondingto the separating plane and the quality limits, and the indicatingpositions of the laser transmitter element are supplied to a computerfor controlling in some cases an optimizing saw.

Marking stations of the above mentioned general type are known in theart. One of such marking stations is operative for stopping the timberupon recognition of a location to be indicated. It has been shown onHannover Fair Ligna 1987 between May 27, 1987, and June 2, 1987, by thecompany Wadkin Leicester, Green Lane Works, Leicester LE5 4PF, England.The laser transmitter element is here the laser itself, and it is movedby the operator along the timber with a rope system to the respectiveindicating position. Because of the high mass of the laser transmitterelement, it is quite difficult and relatively slow. Also, the constantholding of the timber for indicating makes the operation longer in anundesirable manner.

Another marking station is disclosed in the German document DE-GM8,704,684.9. Here a laser 4 is arranged above the timber 3 and theoperator 10 is located laterally of the timber. The laser sends a flatbeam fan 9 perpendicularly to the transporting direction 11. The beamfan 9 shows on the timber 3 the separating plane with a light band 7directly on the upper and front side and is reflected onto the lower andrear side through an inspection mirror 5. The inspection mirror 5 isarranged in an inclined manner near and under the timber 3 relative tothe horizontal plane so that its normal 6 is directed toward the laser4. The timber 3 is brought by the operator through a system of lightbarriers 19 and 21 to a standstill and then displaced manually to therespective indicating position. There an indicating signal is producedand supplied to a computer which is activated by measuring wheels 12, 16and controls for example a cross-cut saw. The structural expenses arevery high. The positioning of the timber 3 manually is time consuming.There is the danger that the eyes 10 of the operator can be hit by thelaser beam 9 reflected from the inspection mirror 5.

A further marking station is disclosed in the German reference DE-OS2,807,670. Here the timber 2 is transported transversely through aninspection zone 10. A stationary laser 26 sends a laser fan 27 onto amirror 23 which is turnable above the inspection zone 10 about an axis24 extending parallel to the movement direction of the timber 2. Througha follow-up control 22 the mirror 23 follows the turning of a handle 18on an operator chair 13. The whole inspection zone 10 including thetimber 2 located in it, is run over with the reflected laser fan 27 byactuation of the handle 18. A laser band 29 shows a separating planewhose position is introduced via a pushbutton 33 on the handle 18 assignal through a conductor 32 into the electronic circuit 31. Thestructural expenses here are also very high. The accuracy of theposition detection is low because of the high turning ratio of the laserfan 27 because of the non-constant and great distance of the operatorfrom the individual longitudinal regions of the timber 2.

The German document DE-OS 3,116,253 discloses a measuring system forexample for a vehicle 1. A measuring bar 8, 21, 25 extends laterallyparallel to the longitudinal axis of the vehicle 1, and a laser 10, 28,30 is stationarily arranged on its one end. The laser sends a bundledlaser beam parallel to the measuring bar. A part of the laser beam isdeviated perpendicularly through a first deviating unit 12, 26, 34 inthe direction of the vehicle 1. The remaining portion of the laser beampasses through the first deviating unit. This remaining portion can bedeviated by a stationary second deviating unit 13 on the other end ofthe measuring bar 8 about 90° along a further measuring bar 9, and theredeviated by a third deviating unit 14 again by 90° in direction of thevehicle 1 as shown in FIG. 1. The remaining portion of the laser beamcan also be deviated in a fourth deviating unit 27, 35 on the firstmeasuring bar 21, 25 in direction of the vehicle 1 as shown in FIGS. 2and 3. The deviating units with the exception of the stationary secondunit 13, are displaceable by the operator 15 manually or by a motoralong their measuring bars and have a detector 40, 41 for markings 42 onthe measuring bar. The detector detects the actual value of eachmeasuring position of its deviating unit and performs the comparisonwith a nominal value for the associated measuring point 2-7 of thevehicle 1.

The German reference DE-OS 2,654,872 discloses a system of searching andoptimizing for example for timber. A stationary laser 30 sends a laserbeam in a beam separator 32, and its both output beams are deviated onsurfaces of a rotatable polygonal mirror 34 and then on several mirrors36, 38 and 40, 42, 44. Each output beam scans finally a surface of thetimber 10 over an angle 46, 48 in a reciprocating manner. Twophotodetectors 50, 52 and 54, 56 are directed to each surface and supplythe sensing signals in an electronic evaluating circuit forautomatically recognizing defect locations in the timber. This systemrequires high structural and circuitry expenses.

The German reference DE-PS 3,208,042 shows a system for testing ofrunning material, especially a paper web 18, as to non-directionallongitudinal and transverse defects 13 and 14. Here a laser beam from astationary laser 1 is extended, subdivided and stretched until parallelpartial beams 23 strike on a fast rotating polygonal mirror 8. Thepartial beams 23 are reflected on the material web 18 and form on itflying light points along the transversely extending testing line 27.The beams 24 reflected from the material web are received by aphotoelectric converter 16 and converted into signals which areevaluated in an evaluating stage 17.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide amarking station for defect locations and quality limits in timber, whichavoids the disadvantages of the prior art.

More particularly, it is an object of the present invention to provide amarking station for defect locations and quality limits in timber, whichhas an increased output than the known marking stations and provides foran easy and reliable operation by an operator.

In keeping with these objects and with others which will become apparenthereinafter, one feature of the present invention resides, brieflystated, in a marking station of the above mentioned general type inwhich a laser transmitter element is formed as a first mirror, a laseris arranged stationarily, a laser beam of the laser extends parallel toa movement direction of the timber and impinges on the first mirror, thefirst mirror deviates the laser beam transversely to the movementdirection in a plane as a laser fan, and a first part of the laser fanimpinges directly on a first side surface of the timber facing towardthe first mirror and also on an upper surface of the timber andindicates there the respective separating plane and quality limit.

Because of the stationary arrangement of the laser and the formation ofthe laser transmitter element as a mirror, the laser transmitter elementbecomes very light. The mirror can be moved easily and fast by theoperator to the desired indicating position. The mirror becomes somovable that normally the indication can be provided during the furthermovement of the timber. Only in exceptional cases the operator brakesthe timber for indication to a full stop. As long as the optimalindication is achieved, the associated position data is transmitted bythe operator to the computer. The laser can send a fanned laser beamwhich is then deviated by the mirror and further fanned. For thispurpose, the mirror is formed flat. Advantageously, the mirror deviatesthe laser beam perpendicularly to the movement direction. By forming thelaser transmitting element as a light transmitter and providing aflexible optical waveguide for connecting a stationary laser with thelight transmitter which transmits a laser fan transversely to thetransporting direction, even more lower structural expenses are achievedwith simultaneous increase in the operating reliability of the markingstation.

In accordance with another feature of the present invention, a flatinspection mirror extends stationarily under the timber in the movementdirection, and a second part of the laser fan is reflected by theinspection mirror to a lower surface of the timber and indicates therethe associated separating plane and quality limit. With these features,an indication on the lower surface of the timber as well is achieved bysimple means. For adjusting to the stature and/or the standing positionof the operator, the inspection mirror can be adjusted as to itsinclination relative to the horizontal plane about an axis which extendsparallel to the movement direction. The operator observes the indicationon the lower surface of the timber in the inspection mirror.

Quality limits of an individual timber are indicated by the operatoralso with the laser fan and with their position data are transmitted tothe computer. The computer determines on the base of its programmingwhether the optimizing saw must or must not deliver a saw cut on thequality limit. In contrast to this, a defect location in the timbercontrols the optimizing saw in each case so that it performs a sawingcut both in the first separating plane as well as in the secondseparating plane to eliminate the defect location from the timber. Inthe latter case, with skilled handling of the first mirror by theoperator, both the first and subsequently the second separating planesare indicated with the same first mirror and the positions aretransferred to the computer. These indicators and transmittals of bothseparating planes which follow one another in a short time can takeplace in further moving timber, while the operator can reduce the outputtransporting speed of the timber when needed.

In accordance with a further feature of the present invention, the firstmirror indicates the first separating plane on the timber, while afurther laser transmitter element formed as a second mirror is movedalong the guiding means and parallel to the movement direction by theoperator for indicating the second separating plane on the timber bymeans of a laser fan in the respective indicating position relative tothe timber. The first mirror can be made partially permeable so that apart of the laser beam falls through the first mirror on the secondmirror. When the laser is arranged on the other side of the mirror, thelaser beam falls naturally first on the second mirror, which in the casecan be made partially permeable, and a part of the laser beam passes tothe first mirror.

Still another feature of the present invention is that each of themirrors is mounted on a carriage which is guided by the guiding device.These features enable an especially exact and easy guidance of thecarriages.

With the use of two mirrors, one of the carriages can be provided with ahand switch, and the hand switch can control the distance between bothcarriages and thereby both separating planes. In this manner thedistance between both mirrors are adjusted relative to one another in asimple and fast manner. The carriage of the second mirror can beprovided for example with a drive which is controlled by the hand switchon the other carriage.

The transporting speed of the transporting device can be controlled independence upon the position of the mirror along the guiding device sothat the transporting speed is maximal when the mirror is located in aninlet region of the marking station, and is minimal when the mirror islocated in the outlet region of the marking station. These featuresprevent a situation that the timber leaves the marking station too fast,for example before the completion of the indication and then must bereturned to the marking station. Advantageously, the transporting speedchanges linearly between its extreme values.

The controlled transporting speed can be selectively superposed by abasic transporting speed of a constant value by actuation of a footswitch. This provides for a further possibility for influencing thetransporting speed of the timber in the marking station.

Each mirror can be provided with a first displacement transmitter whichproduces first output signals corresponding to the position of theassociated mirror, and the transporting device can be provided with asecond displacement transmitter which produces second output signalscorresponding to the position of the timber along the transportingdevice, the first and second output signals being entered into thecomputer. In this way the output signals can be produced in a simple andcost-favorable manner and made available for the computer.

The indication station portion can be followed by a marking device ofthe marking station and the marking device can be controlled by thecomputer so that the separating planes and quality limits indicated inthe indicating station portion remain marked on the timber. With thesefeatures, when needed a remaining marking of the previously made laserindications can be achieved. This can be used for control of theoperator when it is feared that the operator performs the laserindicator on the timber not sufficiently thoroughly. The marking devicecan be formed for example as an ink spraying printer.

The novel features which are considered as characteristic for theinvention are set forth in particular in the appended claims. Theinvention itself, however, both as to its construction and its method ofoperation, together with additional objects and advantages thereof, willbe best understood from the following description of specificembodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic plan view of a marking station in accordance withthe present invention with installation parts located before and afterthe same;

FIG. 2 is a schematic perspective view of the marking station inaccordance with the present invention of FIG. 1;

FIG. 3 is a part of a section taken along the line III--III in FIG. 2;

FIG. 4 is a side view of another embodiment of the invention with amirror which is movable in the transporting direction of the timber, asseen by an operator;

FIG. 5 is an end view of the marking station in accordance with lineV--V in FIG. 4, on an enlarged scale;

FIG. 6 is a view showing a section taken along the line VI--VI in FIG.5;

FIG. 7 is a plan view of the marking station in accordance with thepresent invention according to FIG. 4;

FIG. 8 is a view showing a section taken along the line VIII--VIII inFIG. 7;

FIG. 9 is a view showing a section taken along the line IX--IX in FIG.7;

FIG. 10 is a side view of the marking station according to line X--X inFIG. 7, as seen by the operator;

FIG. 11 is an end view according to line XI--XI in FIG. 7;

FIG. 12 is a schematic perspective view similar to that of FIG. 2 ofanother embodiment of the marking station according to the presentinvention;

FIG. 13 is a partial cross-sectional view taken along the lineXIII--XIII in FIG. 12;

FIG. 14 is a schematic partial plan view of a marking station shown inFIG. 12;

FIG. 15 is a cross-sectional view taken along the line XV--XV in FIG.12;

FIG. 16 is a partial enlarged cross-sectional view taken along the lineXVI--XVI in FIG. 15;

FIG. 17 is a partial cross-sectional view taken along the lineXVII--XVII in FIG. 16; and

FIG. 18 is a partial perspective view of yet another embodiment of amarking station according to the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A marking station 1 in accordance with the present invention is shown inFIG. 1 as a part of an installation to which timber is supplied oneafter the other in the direction of the arrow by a roller conveyor 2.The timber can also be final products which do not allow any remainingmarking. The installation includes a cutting device 3 for processingtimber of up to nine qualities. An optimization of the timber use withconsideration of different qualities and prices for reaching aneconomical solution must be provided.

A timber can have for example several quality stages. The transitionbetween neighboring quality stages is indicated in the marking station 1with a laser beam supplied by a stationary laser 4. Similarly,separating planes before and after a location of defect in the timbercan be indicated with the laser beam. This indication is performed inthat an operator 5 deviates the laser beam which extends from the laser4 parallel to a movement direction 6 of the timber in the markingstation 1, the deviation is carried by a mirror which is not shown inFIG. 1 and advantageously perpendicularly to the movement direction 6 indirection of the timber. The indications can be obtained during therunning timber or also in its rest position.

Each indication of a quality limit or a separating plane next to alocation of defect is introduced by the operator 5 into a computer 7 bypressing a key on a hand switch which is not shown in FIG. 1. In thesame manner the operator 5 introduces different qualities of the timberinto the computer 7 by a keyboard 8.

When the thus registered timber leaves the marking station 1 in themovement direction 6, it arrives at a buffer zone 9 and from there via atransverse conveyor 10 in a transverse direction to a roller conveyor11. The roller conveyor 11 transports the timber in the direction ofarrow to an optimizing saw 12. The latter is formed as an oscillatingsaw and controlled by the computer 7. A sorting system 13 follows theoutput of the optimizing saw 12. It is also controlled by the computer 7which sorts the sawn products.

As shown in FIG. 2, a piece of timber 14 is transported by atransporting device 15 through the marking station 1 in the movementdirection 6. The transporting device 15 has lower rollers 17 which aredriven by a drive 16 with not shown toothed belts, and upper rollers 18which are arranged in alignment with the lower rollers 17 in a verticaldirection. The upper rollers 18 are movable in a vertical direction toadjust to different thickness of the timber and are supported in afreely rotatable manner. The details of this device will be described indetail in another embodiment in connection with FIGS. 4-11. Thetransporting device 15 is supported on a frame 19 of the marking station1, and the laser 4 is stationarily mounted on the same.

A foot switch 20 is provided for the operator. Its actuation can controlthe transporting speed of the transporting device 15. For example, byactuation of the foot switch a differently controlled transporting speedcan be superposed by a basic transporting speed of a constant value.

The different control of the transporting speed is performed by a handswitch 21. When the operator turns the hand switch 21 in the directionof the timber 14, the transporting speed increases to a maximum at theabutment of the hand switch 21. When the hand switch 21 is turnedopposite to the rear by the operator, the transporting speed reducesdown to zero. The above mentioned key 22 is located on top of the handswitch 21. By pressing the key 22 the positions of the quality limits orseparating planes on the piece of timber 14 indicated by the laser beam23 are introduced into the computer 7 shown in FIG. 1.

The hand switch 21 is supported on a carriage 24. The carriage 24 ismovable by the operator by hand parallel to the movement direction 6 bya guiding device which is not shown in FIG. 2. A first mirror 25 ismounted on the carriage 24. It deviates a part of the laser beam 23perpendicularly to the movement direction 6 toward the piece of timber14 and forms a laser fan 26. A first separating plane 27 in the movementdirection 6 before a location of defect 28 is indicated on the timber 14by the laser fan 26. The defect location 28 can be a knot, a crack, aresinous wood axudation, etc. The defect location 28 must be removedfrom the piece of timer 14. For this purpose a saw cut is made along thefirst separating plane 27 in the optimizing saw 12 later. A second suchsaw cut is performed along a second separating plane 29 which is alsoindicated in the marking station 1 and introduced by actuation of thekey 22 with its position data into the computer 7 shown in FIG. 1.

In the embodiment of FIG. 2, the second separating plane 29 is indicatedby a further laser fan 30 on the piece of timer 14. The laser fan 30 isproduced by reflection on a partially permeable second mirror 31 whichis mounted on a further carriage 32. The carriage 32 is also movableparallel to the movement direction 6 and along the guiding device. Thefurther carriage 32 is driven by its own drive which is not shown in thedrawings. The drive is activated by reciprocal activation of the handswitch 21 in a plane which is parallel to the movement direction 6. Inthis manner, the further carriage 32 can be moved in a motor-drivenmanner toward and away from the carriage 24 when desired.Correspondingly, the distance between the separating planes 27 and 29can be changed, so that differently long extensions of the defectlocation 28 parallel to the movement direction 6 can be considered andindicated. When the separation planes 27 and 29 are positioned in anoptimal manner relative to the defect location 28, the operator pressesthe key 22 and thereby simultaneously the position data of bothseparating planes 27 and 29 are introduced into the computer 7.

Since the second mirror 31 is partially permeable, a part of the laserbeam 23 can pass to the first mirror 25. An action of the laser beam 23on both mirrors 25 and 31 can also be performed in a different knownmanner.

If instead of the defect location 28 a quality limit is to be indicatedon the timber 14, this is performed with only one of the mirrors 25, 31and corresponding actuation of the key 22 for introducing the positiondata into the computer 7.

The carriage 24 and thereby the first mirror 25 are coupled with a firstdisplacement transmitter 33 which is formed as a rotation transmitter.The coupling is performed by mounting the carriage 24 on a strand 34 ofa toothed belt 35 which rotatably drives the first displacementtransmitter 33 when the carriage 24 is moved along the guiding device.

On the other hand, the transporting device 15 is coupled through itsdrive 16 with a second displacement transmitter 36 which is also formedas a rotation transmitter. The second transmitter 36 produces secondoutput signals corresponding to the position of the timber 14 along thetransporting device 15. These second output signals as well as firstoutput signals produced by the first displacement transmitter 33 areintroduced in a known manner into the computer 7 shown in FIG. 1.

The indication of the quality limits or separating planes 27, 29 isperformed in an indicating station part 37 of the marking station 1. Inthe embodiment of FIG. 2 the indication station part 37 is followed by amarking device 38 which is formed as an ink vapor printer. With themarking device 38 the quality limits and the separating planes 27, 29indicated in the indicating station part 37 can be remainingly marked onthe timber 14.

An inspection mirror 39 is mounted under the power rollers 17 of thetransporting device 15 over a considerable part of the length of themarking station 1. With 15 the help of the inspection mirror 39 theoperator can observe a lower surface 40 of the timber 14 as to thequality limits and defect location 28 as shown in FIG. 3.

As can be seen from FIG. 3 the inspection mirror 39 also serves forreflecting a second part 41 of the respective laser fans 26 and 30toward the lower surface 40 of the timber 14. It also serves forindicating the quality limits and the separating planes 27 and 29 on thelower surface. These indications on the lower surface 40 are observed bythe operator via the inspection mirror 39.

FIG. 3 further shows that a first part 42 of the laser fan 26 fallsdirectly on a first side surface 43 of the timber 14 which faces towardto first mirror 25 and also on an upper surface 44 of the timber 14, andindicates there the associated quality limits or separating planes 27and 29 of FIG. 2.

During these steps a second side surface 45 of the timber 14, whichfaces away of the operator is not indicated with the laser fan 26 forpreventing return reflection of the laser beams toward the operator.Still the second side surface 45 when needed can be observed by theoperator as to the quality limits and defect locations. This isperformed via an auxiliary mirror which will be described in connectionwith a further embodiment.

In all embodiments the like parts are identified with the same referencenumerals.

The further embodiment is shown in FIGS. 4-11. In this embodiment onlythe first carriage 24 with the first mirror 25 are used, while thesecond carriage 32 with the second mirror 31 of FIG. 2 are not used. Dueto the stationary arrangement of the laser 4, the carriage 24 isreleased from all needless masses and can be easily and fast displacedby the operator, so that in the running timber 14 in FIG. 2 theseparating plates 27 and 29 are indicated shortly one after the otherwithout difficulties and by pressing the key 22 can be introduced withtheir position data into the computer 7 of FIG. 1.

In FIG. 4 the toothed belt 35 and the first displacement transmitter 33are turned relative to FIG. 2 by -90° about a horizontal axis. FIG. 4shows parts of a guiding device 46 for the carriage 24 especially one oftwo guiding rods 47 (FIG. 5) on which respectively running rollers 48 ofthe carriage 24 roll. The guiding rods 47 are mounted on a throughgoingsupporting rail 49 which is fixed in FIG. 5 with screws 50 on the frame19. The supporting rail 49 is provided on its ends with adjustableabutments 51 and 52 for displacement limiting of the carriage 24.

The toothed belt 35 is guided over a deviating roller 53 on its endwhich is located away from the first displacement transmitter 33.

One end 54 of flexible conductor arrangement 55 is mounted on thecarriage 24. Its other end 56 is fixed in the vicinity of the firstdisplacement transmitter 33 on the frame 19. Through the flexibleconductor arrangement 55 all electrical functions of the carriage 24 areconnected with the computer 7 of FIG. 1.

The hand switch 21 is removably mounted on a holder 57 of the carriage24.

The small rectangular shape of the flat first mirror 25 can be seen inFIG. 5. The first mirror 25 rests on frame 58 which is adjustablymounted on a lateral projection 60 of the carriage 24 by screw 59.

The holder 57 for the hand switch 21 which is not shown in FIG. 5 isscrewed in a toothed ring 61 radially from outside. It is supported inthe carriage 24 turnably about an axis 62 which is parallel to themovement direction 6 of FIG. 4. The toothed ring 61 has an innertoothing 63 which engages with a pinion 64 rotatably supported on thecarriage 24. Therefore the turning movements of the holder 57 areconverted into corresponding rotary movements of the pinion 64.

FIG. 6 shows a ring 65 which is turnable on an axis 67 fixed on thecarriage 24 by the screw 66. The holder 57 of FIG. 5 is screwed in thering 65. The toothed ring 61 is also fixed on the ring 65. Sealing disc68 and 69 are provided between the ring 65 and toothed ring 61 on theone hand, and the carriage 24 on the other hand. The pinion 64 ismounted on a shaft 70 which is rotatably supported in the axle 67 andcoupled with the movable element of a potentiometer 71. The stationarypart of the potentiometer 71 is fixed for example by glueing on the axle67. An output conductor 72 of the potentiometer 71 is a component of theflexible conductor arrangement 55 of the FIG. 4.

As shown in FIG. 6, the toothed belt 35 is subdivided and fixedlyscrewed with a respective end on a coupling piece 73 and 74. Eachcoupling piece 73 and 74 extends with its free threaded end into thecarriage 24 and is there adjustable with a nut 75 in its axial directionand fixable with a counter nut 76. In this manner the mounting positionof the toothed belt 35 relative to the carriage 24 is adjusted on theone hand, and the tension of the toothed belt 35 is adjusted on theother hand.

FIG. 6 also shows how the end 54 of the flexible conductor arrangement55 is fixed by a clamp 77 with screws 78 on a connection piece 79 of thecarriage 24. For maintaining the visibility, no further electricalconductors of the flexible conductor arrangement 55 are indicated inaddition to the output conductors 72.

FIG. 7 shows the details of the transporting device 15. The drive 16 ismounted on the frame 19 and drives on the one hand the seconddisplacement transmitter 36 and on the other hand a shaft 83 through anelastic coupling 80, an angular transmission 81 and a further elasticcoupling 82. The shaft 83 is rotatably supported in a bearing block 84of the frame 19. A belt pulley 85 and the frontmost lower roller 17 asconsidered in the movement direction 6 are mounted on the shaft 83. Thecentral and the rearmost of the lower rollers 17 are mountedrespectively on a shaft 86 and 87 which are supported in a furtherbearing block 88 of the frame 19. Belt pulleys 89 and 90 are alsomounted on the shaft 86, while a belt pulley 91 which is in alignmentwith the belt pulley 90 is mounted on the shaft 87. An endless toothedrim 92 runs over the belt pulleys 85 and 89 and is tensioned by anadjustable tensioning roller 93. An endless toothed rim 94 is guidedover the belt pulleys 90 and 91 and is tensioned by an adjustabletensioning roller 95. In this manner all three lower rollers 17 aredriven with the same rotary direction and the same peripheral speed. Thetransporting speeds obtained in this manner for the timber 14 can bechanged in the above described manner when needed.

The auxiliary mirror 96 which is mentioned in connection with FIG. 3 isalso shown in FIG. 7. With this mirror the operator can observe thesecond side surface 45 (FIG. 3) of the timber 14 as to the qualitylimits and defect locations. The auxiliary mirror 96 is adjustable as toits inclination about an axis extending parallel to the movementdirection 6. The upper rollers 18 are arranged perpendicularly above thelower roller 17 which are not shown in FIG. 7. The frontmost roller 18is supported in a freely rotatable manner about an axle 97 which ismounted on a cantilever 98 by two rods 99 movable in a verticaldirection. Similarly the central and rearmost upper rollers 18 arefreely rotatably mounted about an axle 100 and 101 which are mounted ona head piece 102 by two rods 103 movable in a vertical direction.

A first light barrier 105 and a second light barrier 106 are arrangedparallel to the longitudinal axes of the rollers 17 and 18 in an inletregion 104 of the marking station 1. In an outlet region 107 of themarking station 1 such light barriers are not needed. Receiver 108 and109 of the light barriers 105 and 106 are mounted near the bearing block88, while holding arms 110 and 111 for transmitters 112 and 113 (FIG.10) of the light barriers 105 and 106 are mounted on a shaft trunion 114of the inspection mirror 39 in an adjustable fashion.

By a timber 14 which runs in the movement direction 6 into the inletregion 104, the first light barriers 105 is darkened. Thereby apneumatic cylinder-piston unit 115 shown in FIG. 10 is actuated and therod 103 with its both upper rollers 18 is pulled downwardly. Thereby thetimber which ran into the inlet region 104 is acted upon the upperrollers 18 with a pressure from above and pressed into driving contactwith the lower rollers 17. In this manner a slippage-free driving of thetimber by the transporting device 15 in the marking station 1 isguaranteed.

Immediately upon leaving the central roller pair 17, 18, the leadingportion of the timber 14 makes dark the second light barrier 106 andactivates in a known manner the electrical transmission paths betweenthe marking station 1 and the computer 7 of FIG. 1. Through the end ofthe timber the light releases one after the other in the light barriers105 and 106.

An additional light barrier is not required in the outlet region 107 foractuating the frontmost upper roller 18 located there, since thisactuation is performed by a known control circuit with pulsescorresponding to the path covered from the beginning of the timber inthe marking station 1. Simultaneously for hitting of the beginning ofthe timber, the rods 99 with the associated upper roller 18 are pulleddownwardly by actuation of a pneumatic cylinder-piston unit 116 of FIGS.9 and 10.

The shaft end 114 is held adjustably in its rotary position by a bearingblock clampable with screws 117. On the opposite side of the inspectionmirror 39, a similar shaft end 119 is mounted in an axial alignment withthe shaft end 114 and held clampingly in the same manner. Thereby theinspection mirror 39 can be adjusted to each desired turning positionabout a longitudinal axis 120 parallel to the movement direction 6.

FIG. 8 shows the details of the construction and support of the shaft83. A flange 121 is welded on the lower end of the shaft 83 as shown inFIG. 8. The lower roller 17 is screwed on the flange 121 with screws122.

FIG. 9 shows the mounting of the cantilever 98 on one of two mutuallyparallel rods 99, and the support of the rod 99 through ball bearings123 in the frame 19. As can be seen from FIG. 11, each of the both rods99 is screwed downwardly by a nut 124 with a yoke plate 125. A cylinder126 of the pneumatic cylinder-piston 116 is mounted between the nuts 124also on the yoke plate 125. A piston rod 127 of the pneumaticcylinder-piston 116 is screwed with the frame 19. The actuation of thepneumatic cylinder-piston unit 116 moves the cylinder 126 with both rods19 up and down, while the piston rod 127 remains stationary.

FIG. 10 shows the upper rollers 18 which are lifted by the pneumaticcylinder-piston unit 115, 116 to their uppermost end position. Thereby amaximum distance between the oppositely located roller pairs 17 and 18is produced. Since the timber has a height which on the one hand issmaller than this maximum roller distance and on the other hand varies,a stroke limit is provided both for the head piece 102 and for thecantilever 98. For this purpose, a threaded pin 128 is provided eachrespectively between the rods 99 and between the rods 103. It is screwedwith its lower end 129 with the frame 19. The threaded pins 128 extendupwardly with the lateral play through openings of the cantilever 98 andhead piece 102 and carry above the same an adjusting nut 130. A feltring 131 is glued on the lower side of the adjusting nut 130. The feltring 131 acts as a damper when the pneumatic cylinder-piston units 115,116 move the head piece 102 or the cantilever 98 upwardly. By adjustingthe adjusting nut 130, the stroke of the upper rollers 18 can beadjusted to the respective thickness of the timber in an optimal manner.

FIG. 11 shows further details of the marking station 1. The upper roller18 is rotatably mounted on the axle 97 of the cantilever 98 throughroller bearings 132 and 133 in a freely-rotatable manner.

In the embodiment of FIG. 12, the laser 4 is stationarily secured to theside wall 140 of the frame 19 with a mounting 141. The laser 4 isprovided with a feed cable 142 and an optical outlet 143. A connectionpart 144 of a flexible optical waveguide 145 is connected with theoptical outlet 143. The optical waveguide 145 can, for example, be madeof a glass fiber cable. The other end of the connection part 144 ismerged into a stationary second end 146 of the optical waveguide 145. Aportion of the optical waveguide 145 is arranged in a plane extendingparallel to the transporting (movement) direction 6 whereby the firstend 145 of the optical waveguide 147 is connected with an opticaltransmitter 148. The foregoing portion of the optical waveguide 145 issupported in, per se known, flexible conductor arrangement 55 formed asa power circuit. The light (optical) transmitter 148 is supported on thecarriage 24 and is provided with a handle 149 with which the opticaltransmitter 148 and the carriage 24 are displaceable together along thesupporting rail 49. The key 22 is formed integrally with the handle 149and is easily actuatable by the operator.

FIG. 13 shows a transition from the connection part 144 of the opticalwaveguide 145 in the stationary end 146 of the latter. At the second end146, the optical waveguide 145 is connected by a clip 150 with astationary end section 151 of the flexible conductor arrangement 55. Thesection 151 is fixed on the frame 19.

FIG. 14 shows another end section 152 at the other end of the conductorarrangement 55 which is secured to the carriage 24. The first end 147 ofthe optical guide 145 extends into a coupling 153 of the opticaltransmitter 148. On the side portion of the coupling 153, which isopposite to that associated with the waveguide 145, there is arranged arouting housing 154 of the optical transmitter 148 out of which thelaser fan 26 is directed as shown by a dash arrow in a planeperpendicular to the transporting direction 6. FIG. 15 shows in moredetails arrangement of parts shown only relatively schematically in FIG.12.

As shown by a double arrow in FIG. 15, the handle 149 is movable inopposite direction for changing the transporting speed of the timber 14in the transporting direction 6.

As shown in FIG. 16, the waveguide 145 is secured to the coupling 153with a cap screw 155. The first end 147 of the waveguide 145 projectsinto a tubular part 156 of the coupling 153. The first end 147 of thewaveguide 145 irradiates a dash light cone onto a collimator lens 157that transforms the light cone into a beam 158 of rays parallel to itsoptical axis. The beam 158 enters a chamber 159 of the routing housing154 and falls onto a deviating mirror 160 wherefrom the rays aredirected to a cylindrical lens 161 transverse thereto. The laser fan 26projects from the lens 161.

As shown in FIG. 17, the optical transmitter 148 is adjustable relativeto the carriage 24 by means of longitudinal openings 162 and 163. Therouting housing 154 is provided with a recess 164 that defines a centralwindow 165 for light exit. In this embodiment, the laser fan 26 whenleaving the lens 161, still has a certain width but converges until itimpinges on the timber 14, to such an extent that the separating plane27 or 29 or the quality limits can be indicated with a sufficientlynarrow laser beam.

In FIG. 18, the laser 4 is fixed to the, frame 19 by supports 166 insuch a manner that the longitudinal axis of the laser 4 is coaxial withthe longitudinal axis of the waveguide 145.

Such a mounting permits to do away with the connection part 144 of thewaveguide 145.

It will be understood that each of the elements described above, or twoor more together, may also find a useful application in other types ofconstructions differing from the types described above.

While the invention has been illustrated and described as embodied in amarking station for timber, it is not intended to be limited to thedetails shown, since various modifications and structural changes may bemade without departing in any way from the spirit of the presentinvention.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can, by applying current knowledge,readily adapt it for various applications without omitting featuresthat, from the standpoint of prior art, fairly constitute essentialcharacteristics of the generic or specific aspects of this invention.

What is claimed as new and desired to be protected by Letters Patent isset forth in the appended claims.

What is claimed is:
 1. A marking station for defect locations andquality limits in timber, comprising a transporting device arranged totransport a timber in a movement direction through the marking station;a device for changing a transporting speed of the timber in the markingstation; an indicating station part provided with a laser transmittingelement comprising a light transmitter and operative for indicating onthe timber with a laser beam a first separating plane in the movementdirection before a defect location and a second separating plane in themovement direction behind the defect location as well as for indicatingquality limits, said laser transmitting element being movable by anoperator along guiding means parallel to the movement direction relativeto the timber to indicating positions corresponding to the separatingplanes and the quality limits; a computer receiving the indicatingpositions of said laser transmitting element in the movement direction;a stationary laser connected to said light transmitter through aflexible optical waveguide; and said light transmitter transmitting alaser fan transversely to said movement direction, so that a first partof said laser fan directly impinges on a first side surface of thetimber which faces toward said light transmitter and also on an uppersurface of the timber to indicate thereon the associated separatingplane and quality limit.
 2. A marking station as defined in claim 1,wherein at least a portion of said optical waveguide is arranged in aplane extending parallel to said movement direction, said opticalwaveguide having a first end connected to said light transmitter and asecond end arranged stationarily.
 3. A marking station as defined inclaim 2, wherein said optical waveguide includes a connection portionfor connecting said laser with said second end.
 4. A marking station asdefined in claim 1, wherein said optical waveguide comprises a first endconnected to said light transmitter; said light transmitter comprising alight outlet; an optical system being connected between said first endand said light outlet.
 5. A marking station as defined in claim 1; andfurther comprising an optimizing saw arranged to cut the timber in anoptimal manner and controlled by said computer.
 6. A marking station asdefined in claim 1; and further comprising a flat inspection mirrorwhich is arranged stationarily under a path of the timber and extends insaid movement direction, said inspection mirror being located so that asecond part of said laser fan is reflected from said inspection mirrorto a lower surface of the timber and indicates there the associatedseparating plane and quality limit.
 7. A marking station as defined inclaim 1; and further comprising a carriage guided by said guiding means,said lower transmitting element being mounted on said carriage.
 8. Amarking station as defined in claim 1; and further comprising an inletregion and an outlet region, said transporting speed of saidtransporting device being controllable in dependence upon a position ofsaid laser transmitting element along said guiding means so that thetransporting speed is maximal when said laser transmitting element islocated in said inlet region and is minimal when said laser transmittingelement is located in said outlet region.
 9. A marking station asdefined in claim 8; and further comprising means for selectivelysuperposing onto the controllable transporting speed a basictransporting speed of a constant value.
 10. A marking station as definedin claim 9, wherein said means for selectively superposing the basictransporting speed includes a foot switch actuatable by an operator. 11.A marking station as defined in claim 1; and further comprising a firstdisplacement transmitter coupled with said laser transmitting elementand producing first output signals corresponding to a position of saidlaser transmitting element along said guiding means, and a seconddisplacement transmitter coupled with said transporting device andproducing second output signals corresponding to a position of thetimber along said transporting device, said computer receiving saidfirst output signals and said second output signals.
 12. A markingstation as defined in claim 1; and further comprising a marking devicelocated after said indicating station part and arranged to remaininglymark the separating planes and the quality limits indicated in saidindicating station part, said marking device being controlled by saidcomputer.